Take four of them and wire them in parallel. Do this four times. Now wire the four sets of four in series. Firstly, its 1/8+1/8+1/8+1/8=1/2 is 2 ohms. The magic number (the answer) for paralleled resistance is the denominator of the added inverse of the resistance of each speaker. When you add the four paralleled sets together, then it's 2+2+2+2 when they are series wired. With those NSB's wired in the above method, you will know you are right when the array measures ~7.4 ohms or so. You might care to drill out the small lug (3/32 or 5/64) on the nsb's so it will accept a 16 ga. wire directly. I solder the tails on the half the speakers before mounting just 'cause it's easier. Put the pipes up on ebay. You'll never look back after you fire up those arrays.
Good luck!